|extern int quantum_gate_counter(int inc);|
libquantum keeps track of the number of all quantum operations run during the execution of a program. This functions allows you to increase the counter by inc steps. The counter can be set to zero by passing a negative increment. The function always returns the current value of the counter.
|extern float quantum_prob(COMPLEX_FLOAT a);|
The probability for a basis state can be determined with this function. The argument is a complex number, usually a probability amplitude of a basis state. The return value is the square of the absolute value of the complex number, i.e. .
Of course, this function is not available on a real quantum computer, since the quantum state is not observable.
|extern int quantum_getwidth(int n);|
To determine the number of qubits required to encode a classical number, this function can be used. The return value is .
|extern const char * quantum_get_version();|
Returns a string containing the version of libquantum.
|extern void quantum_print_timeop(int width, void f(quantum_reg *));|
Prints the time evolution operator acting on width qubits by running the operations within the function f. The function is called with a single argument, which is a pointer to a quantum register.